Breakdown of Jesu li tri i tri šest?
biti
to be (sam, si, je)
i
and (additive)
li
question particle
tri
three
Questions & Answers about Jesu li tri i tri šest?
Why does this sentence use the plural verb jesu (they are) instead of the singular je (it is)?
Because you are connecting two numbers with i (and). Just like in English where you can say 'Are three and three six?', Croatian treats 'three and three' as a plural subject here, so it takes the plural verb.
I learned that 'they are' is su. Why is it jesu in this sentence?
Su is a short, unstressed word (a clitic), and in Croatian, these short forms cannot be the very first word in a sentence. To ask a yes/no question starting with 'are', you must use the long, emphatic form of the verb. The long form of su is jesu.
Is it normal to use i (and) for 'plus' in Croatian math?
Yes, for simple, everyday addition, native speakers often just use i (and). You can also use the actual word plus, but if you do, the verb usually changes to singular: Tri plus tri je šest.
Are tri and šest the exact words I would use if I were just counting out loud?
Yes! When reading basic math problems like this, you just use the exact same bare number words you learned for counting out loud. They do not change form or need any special endings here.